The Brain and Mind Institute and Department of Psychology, University of Western Ontario, London, Ontario, Canada.
Neuropsychologia. 2012 Nov;50(13):2981-91. doi: 10.1016/j.neuropsychologia.2012.07.030. Epub 2012 Jul 27.
In déjà vu, a phenomenological impression of familiarity for the current visual environment is experienced with a sense that it should in fact not feel familiar. The fleeting nature of this phenomenon in daily life, and the difficulty in developing experimental paradigms to elicit it, has hindered progress in understanding déjà vu. Some neurological patients with temporal-lobe epilepsy (TLE) consistently experience déjà vu at the onset of their seizures. An investigation of such patients offers a unique opportunity to shed light on its possible underlying mechanisms. In the present study, we sought to determine whether unilateral TLE patients with déjà vu (TLE+) show a unique pattern of interictal memory deficits that selectively affect familiarity assessment. In Experiment 1, we employed a Remember-Know paradigm for categorized visual scenes and found evidence for impairments that were limited to familiarity-based responses. In Experiment 2, we administered an exclusion task for highly similar categorized visual scenes that placed both recognition processes in opposition. TLE+ patients again displayed recognition impairments, and these impairments spared their ability to engage recollective processes so as to counteract familiarity. The selective deficits we observed in TLE+ patients contrasted with the broader pattern of recognition-memory impairments that was present in a control group of unilateral patients without déjà vu (TLE-). MRI volumetry revealed that ipsilateral medial temporal structures were less broadly affected in TLE+ than in TLE- patients, with a trend for more focal volume reductions in the rhinal cortices of the TLE+ group. The current findings establish a first empirical link between déjà vu in TLE and processes of familiarity assessment, as defined and measured in current cognitive models. They also reveal a pattern of selectivity in recognition impairments that is rarely observed and, thus, of significant theoretical interest to the memory literature at large.
在既视感中，患者会体验到一种当前视觉环境熟悉的现象，同时有一种感觉，即这种感觉实际上不应该熟悉。这种现象在日常生活中的短暂性，以及开发诱发它的实验范式的困难，阻碍了对既视感的理解。一些颞叶癫痫（TLE）的神经科患者在癫痫发作前一直经历既视感。对这些患者的研究为揭示其可能的潜在机制提供了独特的机会。在本研究中，我们试图确定是否存在既视感（TLE+）的单侧 TLE 患者是否存在独特的间歇性记忆缺陷模式，这些缺陷模式会选择性地影响熟悉度评估。在实验 1 中，我们采用了分类视觉场景的“记得-知道”范式，发现了仅影响熟悉度反应的损伤证据。在实验 2 中，我们对高度相似的分类视觉场景进行了排除任务，这使得识别过程相互对立。TLE+患者再次表现出识别障碍，这些障碍使他们无法进行回忆过程，以抵消熟悉度。我们在 TLE+患者中观察到的选择性缺陷与单侧无既视感（TLE-）患者对照组中存在的更广泛的识别记忆障碍模式形成对比。MRI 体积测量显示，同侧内侧颞叶结构在 TLE+患者中受影响程度不如 TLE-患者广泛，TLE+组的嗅皮质体积减少趋势更为明显。目前的研究结果在 TLE 中的既视感与当前认知模型中定义和测量的熟悉度评估过程之间建立了第一个经验联系。它们还揭示了一种很少观察到的识别障碍选择性模式，因此对整个记忆文献具有重要的理论意义。
